I just recently returned to the r/c hobby and have started assembling some ARFs. Last night I joined two wing halfs with epoxy. This morning when I examed the wing it appeared to be solid however the plate that had some left-over epoxy was still slightly tacky. In looking at the bottles it appears that I used the correct portions of epoxy and hardner. What gives?? Ihave used this glue before with no problems. Will it eventually cure? Thanks in advance for your help.